China: First to the Far Side

Marianne Dyson, November 2018

No spacecraft has ever landed on the lunar far side. The only human-made object on the far side currently is NASA’s Ranger 4 that crashed east of Korolev crater (about 15 degrees south of the equator) in April 1962. But that is about to change!

If all goes well this December, the Chinese Chang’E-4 (named after a mythological Moon goddess) will earn the title of first to the far side. This spacecraft is a lander/rover combination similar to the impressive 2013 Chinese lunar mission called Chang’E-3. Its Yutu (rabbit) rover successfully explored the Bay of Rainbows (Moon’s left “eyebrow”) and returned exciting new scientific data about the lunar surface and subsurface.

The far side of the Moon is never visible from Earth, making direct communications impossible. Therefore, to communicate with the spacecraft and rover on the surface, the Chinese deployed a relay satellite called Queqia (meaning “magpie bridge” from Chinese folklore) earlier this year. Since June, it has been in a 28-day orbit around the Earth-Moon L2 Lagrange point, which is about 37,000 miles (60,000 kilometers) beyond the Moon.

Chang’E-4’s landing area will be in Von Kármán Crater which is near the center of the far side and about 45 degrees south of the lunar equator. This crater lies on top what may be the most ancient preserved impact in the solar system, called the South Pole Aitkin (SPA) Basin. From orbit around the Moon, the SPA Basin appears as a large dark bruise that is more than 8 km (5 mi) deep and has a diameter of 2500 km (1550 mi) which is about a fourth of the Moon’s circumference. [Ref: NASA Lunar Reconnaissance Orbiter]

Von Karman Crater
The rectangle shows the landing area selected for Chang’E-4, an area about 55 by 25 km (34 x 15 mi.) wide within Von Kármán crater on the lunar far side. Ba Jie is the small (about 3 km/1.8 mi) crater to the west of the landing zone. [Image credit: LROC WAC Global Mosaic, NASA/GSFC/Arizona State University, rectangle is plotted based on Wu W R, et al., 2017]
The floor of Von Kármán crater was selected because it is relatively flat, with no more than about 197 feet (60 meters) of elevation change in topography. The rover will map the thickness of the regolith (lunar soil) in this area, which should help researchers to date the age of Von Kármán’s formation and anchor a geological timeline for much of the lunar far side.

Several countries, though not the United States, are actively involved in Chang’E-4. Germany is providing a lunar neutron and radiation dose detector for the lander, Sweden is contributing a neutral atom detector for the rover, and the Netherlands provided a low-frequency radio spectrometer for the Queqia relay satellite.

Dr. Jun Huang of the Planetary Sciences Institute, China University of Geosciences in Wuhan noted that one of the public education experiments on the lander will concern studying a tiny ecosystem including vegetables and worms. These items will be the first non-human living things (other than bacteria left behind on spacecraft) to reach the surface of the Moon.

But perhaps the most exciting thing about this first exploration of the lunar far side is that the Chinese have embarked on a well-planned step-by-step approach to building space capabilities that will directly lead to human space settlements. After Chang’E-4 comes Chang’E-5, an ambitious lunar sample return.

Chinese Lunar Research Station
CR1 and CR2 show two possible locations for the Chinese Research Station near Shackleton crater at the lunar south pole. [Image credit: Chinese Academy of Sciences, General Office of Lunar and Deep Space Exploration, presented at Microsymposium 59, March 17, 2018 by Dr. Chun Lai Li.]
After that, they will use robotic missions to further explore the lunar far side south polar region. Their 10-year plan, which they have followed very closely, has these missions launching in 2023 with humans arriving as soon as 2030. While NASA’s attention is focused on space stations in high lunar orbits, the Chinese may become not only the first to land a spacecraft on the far side, but humans, too.

Writing about Space

My article, “Chinese Planetary Exploration Plans” with more detail about the Chinese space program is in the 2018-4 (current) issue of Ad Astra magazine. To get your copy, join NSS!

To the Moon and Back: My Apollo 11 Adventure, a pop-up book coauthored with Buzz Aldrin with art by Bruce Foster, is available for now from Amazon. Get one for all the kids, big and small, in your family!

My science fact article, “In Defense of the Planet,” is in the Nov/Dec 2018 issue of Analog. Paper or eBook subscriptions available.

The Right Stuff to be a Flight Director

Marianne Dyson, October 2018

Recently NASA announced the first woman, Holly Ridings, to be selected as Chief of the Flight Director’s Office. Flight directors lead the team of flight controllers in Mission Control. The Chief Flight Director is their boss. To reach this position, a person must demonstrate a high level of integrity: like Randy Stone (1944-2013) who similarly rose up from flight controller to flight director to chief flight director (and eventually led Mission Operations). I’d like to share his story via an excerpt from my memoir.

BEGIN EXCERPT (omissions marked with three dots … )

Diane [Freeman] and I were on the Ascent, or Silver Team, for STS-1. Our Flight Director was Neil Hutchinson who expected only the best and no excuses. And well he should. If something were going to break, it’d most likely happen during the dynamic ascent phase.

About a week before launch, Mission Operations Director Gene Kranz called the Silver Team into the auditorium in Building 30. His speech wasn’t the “go team” speech that I’d expected. It was more of a warning and a blessing mixed into one. He reminded us that the space shuttle was the most complex vehicle ever designed by man. “Things break and fail,” he said bluntly. “But,” he added, “You won’t fail.” He said that each of us had been trained more thoroughly for this flight than any team in history. Our managers and the crew were counting on us to make the right calls at the right time. He said he trusted us and that we should in turn trust each other and trust our training. He left us with the sobering absolution that “If the mission fails, it won’t be because of something you did.”

We filed out of the auditorium quietly, each of us lost in thought. No one had ever flown such an unwieldy vehicle, an airplane with stubby little wings strapped to a giant tank with rockets bolted onto the sides. Did we really know what we were doing? Apparently, Mr. Kranz felt that we did, as much as anyone could in a test program. After all, if we knew everything about how this vehicle would fly, we wouldn’t need test flights. He’d expressed the ultimate confidence in us without any false pretenses. He’d sat in on all the long sims. He’d seen us wrestle with failures and find ways to work around them. He knew every one of us by name–had questioned us in briefings, in meetings, and seen us let off steam at social events. He trusted us to do everything humanly possible to prevent or mitigate the consequences of any failures.

Even though I was just a lowly Timeline 2, I felt an immense responsibility to justify Mr. Kranz’s confidence in me. This was no game or simulation. Two men I’d worked with for more than two years were going to eat steak and eggs for breakfast, suit up, and climb aboard the Space Shuttle Columbia. The procedures I’d written for transitioning the computers, for opening the payload bay doors, for what to do if the FES [Flash Evaporator System] or Freon loops, or the primary computers failed, were stowed onboard. My name was on the inside cover of those books. Though others had reviewed and approved them, I felt responsible for those procedures.

I was too keyed up to sleep the night before the launch, scheduled for 45 minutes after sunrise, Florida time, on Friday, April 10. ….  I wore a patriotic white jacket and a blue and white striped shirt. I proudly put my STS-1 and my silver team pins on the lapel of my jacket. I headed out, briefcase and sack lunch in hand. …

Once at my console, I fished a small instamatic camera out of my briefcase. We weren’t supposed to have cameras, but I hoped no one would mind if I took a few snapshots in the back room. I popped the square flashbulb on top. I took a photo of the row of controllers, with Diane in front. I handed the camera to Diane to take one of me. Unknown to us in those days of film cameras, all these pictures blurred. Afraid a manager might yell at me, I put the camera away. …

Marianne Dyson, 1981
Marianne Dyson during STS-1 launch abort, 1981

Like in football games where the clock is stopped for time-outs, the countdown clock stops at certain times in the prelaunch preparations while controllers check data. During the hold at T-2 hours and 4 minutes, Young and Crippen were strapped into their ejection seats. If anything happened during the launch or the latter part of entry (below about 100,000 feet), those seats would blow them out of the cockpit. This capability was only available during the first four test flights and was the reason the crew size was limited to two astronauts.

Even though the Launch Control Center at Kennedy was in charge until the vehicle cleared the launch tower, Houston Flight had to give a “go” for the launch to occur. Hutchinson wouldn’t give that go unless he got a go from each member of the Silver Team. The countdown proceeded until the T-20-minute hold. Everything was going great, and we all refreshed our coffee and made final trips to the restroom.

When I plugged my headset back in, I heard a heated discussion on the data processing system loop. As DPS Randy Stone (1944-2013) related in his oral history session, “When we came out of the T-minus-twenty-minute hold, we had four good primary computers, but the backup computer couldn’t see two of the flight control strings in the vehicle. Clearly it was unacceptable to fly your first flight when the two systems didn’t match,” he said. …

Stone said, “My back room was analyzing the data, and … they came to me on the loop and said, ‘There is nothing wrong with the backup. The problem is with the primary computer system. It’s not sending data.’”

I heard Stone call the Flight Director, “Flight, DPS.”

“Go, DPS,” Hutchinson said.

“We want to transition everything back to OPS-9.”

OPS-9 was the prelaunch mode for the computers. So they did this and Stone said, “The computers all looked good, and I’m thinking, ‘Man, if we come out of this hold and it works, am I go to fly?’ I’ve talked to my back room, and Gerry Knori and Jim Hill and Bill Lychwick all said, ‘We don’t understand it. We don’t want to fly today.’”

By now the countdown had progressed to T-9-minutes and was on hold for ten minutes. The weather was beautiful. The astronauts were strapped in and ready. Hundreds of thousands of people, including politicians and celebrities, were waiting and watching. And so was Mr. Kranz who’d reminded us all of the seriousness of our responsibilities. The decision rested heavily on Stone’s shoulders.

While he contemplated the computer issues, one of the fuel cells showed abnormal acid levels. The countdown was halted. The fuel cell was quickly determined to be okay, and the countdown was set to resume after the hold.

Stone said, “I made a decision with the help of the folks in the back room that it is not the right day to go fly. So I got on the flight loop. … I said, ‘Flight, I don’t care what happens when we come out of the T-minus-nine-minute hold. DPS is no go for launch.’ And man, you could have heard a pin drop in that room. I mean, it went from a lot of buzz to quiet.”

On the Flight loop, Hutchinson asked, “Are you sure you are no go for launch?”

Stone said, “Yes, sir. We do not understand what happened here. If it works this next time, I can’t guarantee it’s going to work through ascent, and I can’t guarantee it’s going to work when we bring these computers back alive to do entry. I am no go for launch.”

When we came out of the hold, the computers still didn’t match up. But even if they had, Stone had already made his decision, and so had Hutchinson. Would the managers support this decision to scrub the launch? It was an expensive choice. The eyes of the world were on us, and the launch had been slipped again and again. But a flight controller had trusted his training and made a difficult call, knowing that even worse consequences might have resulted if he hadn’t.

The team at KSC and in Houston worked for three hours unsuccessfully to trace the source of the computer problem. Finally, the Launch Director halted the countdown clock and declared a scrub at just before 10 a. m. Young and Crippen, who had been lying on their backs for six hours, were helped out of the cockpit.

Stone said, “My claim to fame is I was the guy that was no go for launch on STS-1 before we ever found out if it was okay or was going to work when we came out of the hold again. And truly, I believe that was a turning point in my decision-making process where I was confident enough to say no in an environment when everybody else wanted to say yes.”

After the flight, the Center Director Chris Kraft, Jr. pulled Stone aside and told him that he’d made the right call, scrubbing the launch. About three weeks later, Stone was selected to become a flight director. …

We soon learned that the problem with the computers was a timing error that caused them not to sync up with the backup machine. …. IBM fixed the flaw in the software after the first flight so it couldn’t happen again.

END EXCERPT

So please join me in congratulating Holly Ridings on her selection as Chief of the Flight Directors Office. She is an inspiration to all.

Writing about Space

To the Moon and Back: My Apollo 11 Adventure, a pop-up book from National Geographic that I coauthored with Buzz Aldrin, with art by Bruce Foster, is available for order now from Amazon. Look for it in stores everywhere on October 16.

My science fact article, “In Defense of the Planet,” is in the Nov/Dec 2018 issue of Analog. Get your subscription now!

Speaking about Space

Teachers, librarians, and event organizers, please consider me for Author Visits. Writers and publishers, I offer science consulting, content and technical editing.

October 2, Instructor for first class of Women and Space course at Rice University’s Glasscock School of Continuing Studies.

October 12, Featured speaker on Friday 11 to noon, book signing 12-12:30 at the NatGeo Cengage Booth #408 at the National Science Teachers Association conference in Reno, Nevada.

October 27, Saturday, 10-2. Free & Open to the Public: NASA Johnson Space Center Open House. Look for copies of To the Moon and Back at the JSC Employees Exchange Store either at the tent by the Saturn V or in Building 3 cafeteria.

Triangles to Mars

Marianne Dyson, July 2018

At the end of July, Mars will be its brightest in 15 years because it will be only 35.8 million miles (57.6 million kilometers) away. Since no one has ever been to Mars, how do we know this distance so precisely?

Triangles! If the length of one side and two angles of a triangle are known, the length of the other sides can be calculated. Way back in 1673, Giovanni Cassini (1625-1712) used this knowledge of triangles to estimate the distance to Mars. This method is called parallax. [Ref: A Teacher’s Guide to the Universe: Background: Parallax.]

Half the distance (R in the diagram) between two locations on Earth is the known (opposite) side of the parallax triangle. One angle is 90 degrees. The other angle is found by observing the object from the two locations (Cassini in Paris and fellow astronomer Jean Richer in French Guiana in 1673). From the two locations (1 and 2 in the diagram), the object appears in a slightly different place in the sky (A and B in diagram) defined by the distant background stars. The difference in position reveals the angle (ɵ in the diagram). Plugging the known distance and measured angle into the tangent equation*, the answer for D is revealed.

Parallax Shift
The distance (D) to a planet or star can be found by observing it from two locations (1 & 2) whose separation (R) is known, and then determining the angle (ɵ) between the observed position in the sky using distant background stars (A and B). Credit: NASA.

*The tangent of ɵ equals the length of the opposite side (R) divided by the length of the adjacent side (D) which is the distance. Because the angle is very small, the tangent is approximately equal to the angle. So the equation simplifies to D (in parsecs) equals R (in Astronomical Units) divided by ɵ (in arc seconds).

The farther away an object is, the “taller” the triangle and the smaller the angle, making it difficult to measure very accurately. Thus parallax measurements to planets are easier when the planet is at opposition, on the same side of the sun as Earth. Mars opposition occurs every 26 months. But the orbit of Mars is an ellipse. So the closest to Earth Mars can get is when opposition is near periapsis—when Mars is closest to the sun. Opposition and periapsis coincide every 15 years, and 2018 is one of those years.

An Alternate History

The years when opposition and periapsis coincide are also the best years, in terms of fuel and time spent in transit, to send spacecraft to Mars. Back in 1990, I wrote a science fiction story about a group of astronauts preparing for a trip to Mars this year so that they would take the first steps on Mars before the 50th anniversary of Apollo 11’s landing on the Moon. I rediscovered this manuscript (it was not in digital form!) in my closet recently and am in the process of turning it into an alternate history novel.

So when I go out to view Mars later this month, I’ll be imagining my crew on their way there this summer. If they had followed the trajectory of InSight that launched on May 5, they’d be arriving on Mars on Monday, November 26. [Ref: Planetary Society.] But to reduce radiation exposure, they would likely have launched on May 18, “passed” InSight en route, and would be arriving on Mars on September 10, 2018. Would that day become a holiday on Mars?

Imagine if the current crew of six (which includes only one woman) up on the International Space Station were instead on their way to Mars. Would they be worried about the global Martian dust storm in progress right now?  Would every kid in the country know everything there is to know about their planned landing area in Isidis Planitia? I can almost hear my young self proudly telling my mom that this part of Mars was named after the Egyptian goddess of heaven and fertility.

Mars in the Teapot

Though no humans are yet scheduled to travel to Mars, at least we have learned how to measure the distance and send spacecraft there. InSight is a pretty cool little spacecraft, too. It has a probe that is a self-hammering mechanism that will pound itself into the ground, up to 16 feet (5 meters). It relays data back via its tether to the lander. What might it find under the surface?

So later this month, look for Mars in the southeast evening sky near the Sagittarius “teapot.” Mars will be glowing orange below and to the left of the teapot with yellow Saturn above the top. Saturn was at opposition on June 27. How far is it to Saturn? If you have a good telescope, and a friend on the other side of the planet, you can figure it out yourself using triangles. Or you can just Google the answer!

Writing about Space

My guest editorial on Gender Parity is in the July/August issue of Analog. You can read it free online, but you might want to subscribe so you can read my fact article “In Defense of the Planet” in the upcoming Nov/Dec issue. I also did a Q&A with the magazine that should be posted later this month on the Astounding Analog Companion.

My next book, coauthored with Buzz Aldrin, To the Moon and Back: My Apollo 11 Adventure, a pop-up book from National Geographic, is available for preorder now from Amazon. Look for it in stores in October.

Speaking about Space

I offer programs for school-aged children up through senior citizens, as well as science workshops for students and teachers. Please consider me for Author Visits.

September 21-23, Science GOH at FenCon XV in Dallas. See their website for program details. Writer GOH is Larry Niven.

September 29, Attending SCBWI Houston conference.

October 2, Instructor for first class of Women and Space course at Rice University’s Glasscock School of Continuing Studies.

October 12, Featured speaker on Friday at noon at the National Science Teachers Association conference in Reno, Nevada.

See my contact page for a complete appearance schedule and photos from previous events.

Alan Bean: First Artist on the Moon

Marianne Dyson, June 2018

Apollo 12 Astronaut and Artist Alan Bean who died on May 26, 2018, kindly granted an interview to this former flight controller who was considering a new career as a children’s writer back in 1994. After all these years, I find his words still inspiring, and I hope you will also.

The May 1994 issue of Odyssey Magazine included my interview and photo of Alan Bean. Photo © Marianne Dyson.
The May 1994 issue of Odyssey Magazine included my interview and photo of Alan Bean. Photo ©Marianne Dyson.

First Artist on the Moon: An Interview with Apollo Astronaut Alan Bean

by Marianne J. Dyson

As a boy growing up in Texas, Alan Bean fell in love with flying. He built precise model planes and hung them from the ceiling of his room, “like birds dressed up for a party in shiny decals and brightly colored paints.” Through a determination to always do his best, Bean became a Navy pilot and then a NASA astronaut. In November 1969, he stepped out of the Apollo 12 lunar module and became the fourth man to walk on the moon. He returned to space in 1973 as Commander of Skylab 3, the world’s first space station. Although he has not returned to space for over two decades, he returns often, in spirit. Bean left NASA in 1981 to pursue a new career as a space artist. He recently took out from work on his latest painting at his home studio in Houston, Texas, to talk with ODYSSEY.

The switch from being a test pilot and astronaut to being an artist could be called the ultimate career change. Was the transition difficult?

Well, being a test pilot and an astronaut is a lot more dangerous. You have to have intense training and a certain personality and work habits to be successful and survive. That’s not the case in art, where anyone can create what they feel is art. However, it takes longer to be a good artist. It took me about six years from the time I became an astronaut until I felt I was a really good astronaut. It’s taken me 12 years until I felt I was a really good artist.

You’ve ridden rockets to the moon and walked in space and received all kinds of recognition and awards for those achievements—how do those thrills compare to the rewards you get as an artist?

They’re really about the same. I think the feeling of a job well done on a daily basis, no matter what the job is, is one of the most important things that a person can feel to have a happy life. Awards come from time to time, but effort comes on a daily basis.

I have heard that there is real moon dust in your paintings. Is that true?

I wanted to put moondust in them, but I didn’t have any moon rocks; the government has all of those. But one day I realized NASA gave me the patches from my suit—the NASA patch, the American flag, the Apollo 12 patch. They were dirty with moondust, so not I cut up those patches into little bits and I sprinkle them around in the paintings. There are minute quantities [of the patches and moondust] in all of them.

Which painters that ODYSSEY readers might be familiar with have influenced your work?

American painters Charles Russell and Frederick Remington have inspired me. French artist Claude Monet is my favorite artist. When you look at Remington’s and Russell’s paintings, you can figure out the story they’re telling of a frontier and adventures that occurred on it. If I want to tell the story of this [space] frontier, I’ve go to be able to paint my spaceships as well as they painted their horses; I’ve got to be able to paint my astronauts as well as they painted cowboys and Indians. Now, Moment doesn’t tell stories as well, but he does things that are beautiful to look at. I try to combine some of Remington’s and Russell’s storytelling and realism with some of Monet’s color variety and beauty in my work.

Imagine that in 50 years, you’re still alive and our nation builds an art museum on the moon. What would you say if people ask to name it after you?

I’d say it would be very appropriate because I am the first artist to have painted the moon. Maybe some day they will have an art museum on the moon, and I hope they have a painting or two of mine in there. I’ve never really thought about it. But I think someday it will happen.

END published interview

I still have the audio cassette tape of this interview which of course had to be significantly cut to fit on two pages in a children’s magazine. Not included in the article is perhaps my favorite quote of Alan Bean: “The moon is gray, but I have the desire in my heart to paint these beautiful colors.”

In the yet-unfinished [in May 1994] painting of the moon, the artist [Alan Bean] uses a cathedral of colors similar to those he thinks Monet, his favorite artist, might have used. Photo © Marianne Dyson shown as published in Odyssey Magazine.
In the yet-unfinished [in May 1994] painting of the moon, the artist [Alan Bean] uses a cathedral of colors similar to those he thinks Monet, his favorite artist, might have used. Photo ©Marianne Dyson shown as published in Odyssey Magazine.
I sent him a copy of the magazine after it was published and included a sonnet that he inspired me to write. To honor his advice to put in the effort required to become a “good” writer, I chose the most difficult form of a poem I could think of, one that requires precise rhythm, meter, word choice, and rhyme: a Petrarchan sonnet. (This poem is included in Space Poems.)

The Artist's Moon

a Petrarchan sonnet by Marianne Dyson


The moon is gray, but not for those still free -

to dare the red of love, to stroke the sky

with flaming orange and silver ships that fly

beyond the pallid dawn of history.

The dreamers' moon is cast in rosy light,

a canvas bright with crystal beads and hopes

that lure the spirit high upon its ancient slopes

and paint its hills with hues of future sight.


The hero's brush disturbs the settled lust

of youthful goals, long patient human souls

who yearn with passion's palette for the day

they thrust aside the current veil of dust

and see creation's art, a mural whole

with fingerprints of God in lunar gray.

Writing about Space

Analog readers, watch for my guest editorial on Gender Parity in the July/August issue.

My next book, coauthored with Buzz Aldrin, To the Moon and Back: My Apollo 11 Adventure, a pop-up book from National Geographic, is available for preorder now from Amazon. Look for it in stores in October.

Speaking about Space

I offer programs for school-aged children up through senior citizens, as well as science workshops for students and teachers. Please consider me for Author Visits.

After a talk with students at Laredo Public Library on May 15, 2018, I was interviewed by Telemundo TV. The clip aired during the local evening news. Photo by Rick Carrillo.
After a talk with students at Laredo Public Library on May 15, 2018, I was interviewed by Telemundo TV. The clip aired during the local evening news. Photo by Rick Carrillo.

Thursday, June 7, vendor fair participant, Setting the Trend, Librarians as Leaders conference. Clear Falls High School, 4380 Village Way, League City, TX.

September 21-23, Science GOH at FenCon XV in Dallas. See their website for program details. Writer GOH is Larry Niven.

October 2, Instructor for first class of Women and Space course at Rice University’s Glasscock School of Continuing Studies.

October 12, Featured speaker on Friday at noon at the National Science Teachers Association conference in Reno, Nevada.

See my contact page for a complete appearance schedule and photos from previous events.

Slowing Down from Space

Marianne Dyson May, 2018

Many people mistakenly think that there is no gravity in space, and thus all that’s needed to reach space is to attain a certain altitude. But this is NOT true! Earth’s gravity at the surface is defined as 1g. A simple calculation* shows that the gravity at 200 miles (320 km) altitude is 90 percent of what it is on the surface, or 0.9g.

The reason spacecraft stay in orbit is not because there isn’t any gravity, but because they have attained the speed necessary to balance gravity’s pull. They must go up high enough to avoid running into mountains and the upper atmosphere which would slow them down.

A bit of algebra** proves that the velocity required to stay in an orbit does not depend on the mass of the object, only the mass of Earth and the object’s distance from the center of Earth. For orbits of 200 miles up, the speed is 17,500 mph (28,200 kph). (Note, it takes more energy to speed up a larger mass, but the speed that must be attained is the same.)

To drop to a lower orbit or return to Earth, a spacecraft doesn’t just “step off” a platform in the sky: it must slow down. This happens naturally over time because, though thin, the Earth’s atmosphere extends far into space. This is what happened to Skylab and more recently, to the Chinese space station. To stay in orbit, spacecraft must be periodically boosted.

The key to a safe return from space is to slow down, and slow down gradually.

Slowing down begins by flipping the spacecraft so that the engines are pointed forward, into the direction of travel. To slow down completely would require about the same amount of fuel as it took to reach orbital speed in the first place. On an airless world like the Moon, that is the only way to slow down. But because of Earth’s atmosphere, spacecraft need only fire their engines enough to slip into the atmosphere and then let friction do the rest.

But friction between objects at high speed produces a lot of heat. (Try rubbing your thumb and finger together slowly and then faster and note the difference in heat.) Meteors enter the atmosphere at very high speeds and quickly turn into fireballs. To avoid a similar fate, spacecraft use heat shields to protect the hull and crew. Heat shields can be made of what are called ablative materials such as used during Apollo that burn off and take heat with them; or they may take the form of insulating tiles such as were used on the space shuttles. (Damage to the heat shield is what caused the destruction of Space Shuttle Columbia.)

space shuttle
The space shuttle orbiter was covered with tiles to insulate the aluminum skin underneath from the high temperatures produced by the friction of passing through the Earth’s atmosphere at high speeds. Image: Lockheed Martin.

Once the spacecraft has passed through the upper atmosphere and lost much of its speed to heat, it is still going very fast. Unless it slows down more, it will hit the surface like a speeding car crashing into a wall. To slow down further, winged craft like the space shuttle increase their time in the lower atmosphere by executing “S” turns and then deploying parachutes after touchdown. Capsules like the Russian Soyuz use parachutes while still in the air and fire retrorockets just before touchdown.

So when it comes time to return to Earth from your trip in space, remember to slow down!

cups
Prove that heavy objects do NOT fall faster than light ones, but compact objects DO. Take two identical plastic containers with lids. Put a flashlight battery in one. Seal and drop them both. They hit the floor at the same time. Then take two identical sheets of paper. Crumple one and leave the other flat. Drop them. The compact one hits first. If you did this experiment on the Moon, they would strike at the same time. (Watch an Apollo demonstration.) The speed of falling does not depend on mass. In an atmosphere, objects with more surface area fall more slowly than compact objects.

*The equation for gravity is g=G x M/D² where G is a constant, M is mass, and D is the distance. GM/D² for the surface divided by GM/D² for 200 miles up ends up with all terms except D cancelling out, i.e. 4000×4000/4200×4200=0.9.

**For calculating orbital velocity (v=√GM/r) see Gravitation Calculating Orbital Velocity of a Satellite, Step-by-Step Science.

 

 

Writing about Space

Analog readers, watch for my guest editorial on Gender Parity in the July/August issue.

My next book, coauthored with Buzz Aldrin, To the Moon and Back: My Apollo 11 Adventure, a pop-up book from National Geographic, is available for preorder now from Amazon. Look for it in stores in October.

Speaking about Space

I offer programs for school-aged children up through senior citizens, as well as science workshops for students and teachers. Please consider me for Author Visits.

Nevada Space Center
I was inducted into the Nevada Space Center Hall of Fame on May 5, 2018. Prior to the evening event, I received a T-shirt from Challenger Center Flight Director Jenny McFarlane and former NASA Flight Director Paul Dye. Photo: Nevada Space Center.

Saturday, May 12, 1:00-4:30 PM. Speaking on “How to Publish a Book” at Houston Writers House. Event sold out, but watch for another session to be scheduled.

Tuesday, May 15, 9-10 AM Passion for Space, 10-11 AM, Children’s program, Laredo Public Library.

Tuesday, May 22, author visit to The Westview School.

Friday, May 25, panelist, Comicpalooza, George Brown Convention Center, Houston.

Thursday, June 7, vendor fair participant, Setting the Trend, Librarians as Leaders conference. Clear Falls High School, 4380 Village Way, League City, TX.

September 21-23, Science GOH at FenCon XV in Dallas. See their website for program details. Writer GOH is Larry Niven.

See my website’s contact page for a complete appearance schedule.

Wait! I’m Calling from Space!

By Marianne Dyson

April 2018

My husband almost hung up on a call from the International Space Station. Because no one immediately responded to his hello, he assumed it was just another junk call with a built-in delay before some recorded sales pitch kicked in. Just as he was about to hang up, astronaut TJ Creamer said, “Wait, don’t hang up! It’s TJ calling from the space station!”

The space station is “only” a few hundred miles above the surface of the Earth. We get calls from much greater distances all the time with no delay. So what causes the lag time? The radio signals from the space station first go up all the way to geosynchronous orbit, 22,200 miles up, where the Tracking Data Relay Satellites reside, and then back down to one of the Earth receiving antennas, and finally through ground networks to our house phone. It’s a long journey for that old radio signal that just won’t go any faster than 186,000 miles per second no matter how much you honk your horn.

Still, most people can tolerate a delay of half a second—as the telemarketers have unfortunately discovered. But if one of our astronaut friends one day calls us from the Moon, at 240,000 miles, times two for the round trip, the lag time between our hello and their answer is about two and a half seconds. Click. Better warn us ahead of time!

I saw the gold James Webb Telescope outside the vacuum test chamber at Johnson Space Center in January 2018. Photo © Marianne Dyson.

Calls from farther away, such as the million-mile distance of the Earth-Moon Lagrange Point 2 where the James Webb Telescope will be orbiting, will take more than five seconds each way. Click.

Calling from Mars? Depending if the Earth and Mars are on the same or opposite sides of the sun, the distance varies from half an astronomical unit (AU=93,000,000 miles or one light minute) to 2.5 AU or 4 to 21 minutes each way. Click.

Future messages from Europa out there orbiting Jupiter at 5 AU, would take from a half hour to almost an hour one way. Click. A call from Alpha Centauri at 4.3 light years distance? Sorry, that call can’t be completed as dialed…

No wonder Star Trek and other science fictional universes rely on “subspace” or “ansibles” that conveniently route calls through other dimensions or wormholes to allow the plot to move faster than the posted (light) speed limit.

The consequences of dealing with space lag times offer some interesting challenges for our future pioneers beyond having their friends or family hang up on them. Without being able to call 911 or Mission Control to solve problems, they need to be well-trained and equipped with appropriate tools to handle emergencies. Like Mark Whatney in The Martian, if regular communications fail, they may be forced to use hexadecimal coded signals to communicate. Or they may simply write “SOS” with a rover, rocks, or pieces of their broken spacecraft for the new James Webb Telescope to spot.

So when you answer the phone and hear clicks and no voice: Wait, don’t hang up! It might be a call from space!

Writing about Space

Analog readers, watch for my first guest editorial in the July/August issue!

My next book, coauthored with Buzz Aldrin, To the Moon and Back: My Apollo 11 Adventure, a pop-up book from National Geographic, is available for preorder now from Amazon. Look for it in stores/museums in October.

Buzz is featured on the cover of the winter 2018 issue of Ad Astra, the magazine of the National Space Society, that includes my article, “Space Business Challenges.”

Speaking about Space

Whether you’re looking for a role model for female students, a scientist to run a STEM workshop, or a speaker with some unique stories, please consider an author visit. I offer programs appropriate for school-aged children up through senior citizens, as well as science workshops for students and teachers. See my list of programs on the Author Visits tab of my website.

Saturday, April 21, 8 AM-4 PM. Selling and signing books, new and used, at the Clear Lake Community Association Garage Sale.

Saturday, April 28, 10 AM-2 PM, volunteer for the Grand Opening of Exploration Green.

May 4-6, May the Fourth Celebration, visit to Nevada Space Center Hall of Fame. Speaking about Science and Science Fiction on Friday evening, attending the dedication of the Nevada Challenger Center Redfield Mission Control and giving a Keynote Address on Saturday.

Saturday, May 12, 1:00-4:30 PM. Speaking on “How to Publish a Book” at Houston Writers House event. Register here.

Tuesday, May 15, 9-10 AM Passion for Space, 10-11 AM, Children’s program, Laredo Public Library.

Tuesday, May 22, author visit to The Westview School.

Friday, May 25, panelist, Comicpalooza, George Brown Convention Center, Houston.

Thursday, June 7, vendor fair participant, Setting the Trend, Librarians as Leaders conference. Clear Falls High School, 4380 Village Way, League City, TX.

September 21-23, Science GOH at FenCon XV in Dallas. See their website for program details. Writer GOH is Larry Niven.

See my website’s contact page for a complete appearance schedule.

Make Time for the Stars

by Marianne Dyson

March 2018

Pioneering female astronomer Vera Rubin (1928-2016), who proved the existence of dark matter with her observations of the Andromeda Galaxy, told me that observing the stars out the window by standing on her bed as a child was what inspired her choice of career. I exclaimed, “I did that, too!” [Ref: Space and Astronomy, pp. 210-11]

Yet many children today can’t see the stars in the evening because it is still daylight when they go to bed, especially during the summer months. Thankfully, we have the power to change this by opting out of daylight savings time (DST). Arizona, Hawaii, Puerto Rico, and the Virgin Islands have already opted out. Congress controls standard time and sets the dates for when DST starts and stops (currently second Sunday in March and first Sunday in November), but allows states to opt out. [Ref: USNO Daylight Time]

So at my local precinct convention after the polls closed last Tuesday, I introduced a resolution for Texas to opt out. It passed unanimously.

The main arguments for stopping DST are that it is not effective in saving energy (the original reason it was instituted) and that it increases traffic fatalities.

With more efficient lighting, and increased use of air conditioning, some studies have shown that DST has a marginal or a negative effect on energy use. A study in 2008 showed about a one percent increase in energy consumption in Indiana after adopting DST. The economic impact is even more severe for states like Texas and Arizona with heavy use of air conditioning in hot summer evenings. [Ref. Daylight Saving Time 2018.]

But the strongest reason to opt out of DST is a study of 21 years of time shifting that found an increase in the number of fatal accidents on the Monday following the spring shift (from sleep deprivation), and also on the Sunday following the fall shift (attributed to people staying out later to take advantage of the extra hour). [Ref: Fatal accidents following changes in daylight savings time.]

Moving clocks forward (from about 6:30 AM to 7:30 AM) also puts high school students, who need to arrive by 7:20 AM in my school district, especially at risk as they wait for buses, walk to school, or drive in the dark. Is even the loss of one young life worth having an extra hour of daylight after dinner for two months in the spring and fall?

Note that there is no actual daylight “saved,” it is only shifted from the morning to the evening. For every person who enjoys that hour of light after dinner, there is another that would prefer to jog or walk their dog in the light before heading off to work in the morning.

But if daylight is preferred by the majority in the evening, then perhaps DST should shift forward in the fall and back in the spring, the opposite of the current system. Then, in December, when it is light for only 9-10 hours (less for higher latitudes), it would be light from about 8:30 AM until 6 PM instead of from 7:30 AM to 5 PM. And in June, when it is light for 14-15 hours (longer for higher latitudes), sunset would be about 8 PM instead of 9 PM, and more kids could see the stars before bed. [Ref: timeanddate.com]

If you’d like your state to opt out of daylight savings, I urge you to introduce planks in your party’s platform and share your opinion with your state and Congressional representations. Let’s make time for the stars!

Writing about Space

I’m happy to announce that my novelette, Europa’s Survivors is a finalist in the Analog Readers Poll, and for a limited time (and to help generate nominations for the Hugo Award: deadline is March 16!), Analog is offering it FREE through their website. It is also included in my story collection called Fly Me to the Moon.

My next book, coauthored with Buzz Aldrin, To the Moon and Back: My Apollo 11 Adventure, a pop-up book from National Geographic, is available for preorder now from Amazon. Look for it in stores/museums in October.

In February, I joined a National Assessment of Educational Progress panel of expert educators and fellow children’s authors (shown here L to R: John Alexander, Lulu Delacre, Marianne Dyson, Michael L. Cooper, and Allison Lassieur) to read and choose examples of fourth-grade writing at the basic, proficient, and advanced levels. Participation in this assessment is why there was no February Science Snacks! (Photo courtesy Marianne Dyson)

Speaking about Space

Whether you’re looking for a role model for female students, a scientist to run a STEM workshop, or a speaker with some unique stories, please consider an author visit. I offer programs appropriate for school-aged children up through senior citizens, as well as science workshops for students and teachers. See my list of programs and prices on the Author Visits tab of my website. Book a fall visit before July to lock in current fees. Here’s my upcoming schedule of events:

Wednesday, March 14, 10:30 AM, children’s space activity & book signing, Brazos Bookstore, 2421 Bissonnet St., Houston. 

March 18-23, attending Lunar & Planetary Science Conference as press looking for science stories.

Saturday, March 24, 9AM-3:30 PM. Selling and signing books at the JSC Annual Craft Fair and Flea Market.

Saturday, April 28, 10 AM-2 PM, volunteer for the Grand Opening of Exploration Green.

May 4-6, May the Fourth Celebration, visit to Nevada Space Center Hall of Fame. Speaking about Science and Science Fiction on Friday evening, attending the dedication of the Nevada Challenger Center Redfield Mission Control and giving a Keynote Address on Saturday.

Tuesday, May 15, 9-10 AM Passion for Space, 10-11 AM, Children’s program, Laredo Public Library.

Tuesday, May 22, author visit to The Westview School.

Friday, May 25, panelist, Comicpalooza, George Brown Convention Center, Houston.

See my website’s contact page for a complete appearance schedule.